Occupant protecting device

Abstract

In an occupant protecting device including an expandable bag housed within a belt for holding back an occupant upon collision of a vehicle, an outlet opening 33 1 in a buckle-side duct 28 and an inlet opening 18 3 in a tongue-side duct 18 are opposed to each other through a gap α, and a seal member 35 made of a rubber and integrally provided with an outer lip portion 35 2 and an inner breakable portion 35 3 is mounted to the outlet opening 33 1 . When a gas generated by an inflater upon collision of the vehicle is supplied to the buckle-side duct, the breakable portion 35 3 of the seal member 35 is broken to bring the lip portion 35 2 into close contact with the inlet opening 18 3 , so that the gas is supplied from the buckle-side duct 28 through the tongue-side duct 18 to a shoulder belt, thereby expanding a bag housed in the shoulder belt. Thus, it is possible to easily and reliably perform the sealing of a gas passage in a connection between a buckle 31 and a tongue 19.

What is claimed is:  
     
       1. An occupant protecting device comprising: 
       a buckle-side duct integral with a buckle supported on a seat; and  
       a tongue-side duct integral with a tongue supported on a belt,  
       said buckle and said tongue being coupled to each other to place an outlet opening in said buckle-side duct in a state opposed to an inlet opening in said tongue-side duct,  
       said belt being expanded by a gas, generated by an inflater upon collision of a vehicle, supplied to said belt through said buckle-side duct and said tongue-side duct,  
       said outlet opening in said buckle-side duct being closed by a membrane-shaped seal member which is integrally provided with a lip portion at a peripheral edge thereof and a central breakable portion, and  
       a connection between said outlet and inlet openings being created upon breaking of said breakable portion of said seal member by the pressure of the gas generated by said inflater upon collision of the vehicle, bringing said lip portion into contact with said inlet opening in said tongue-side duct and sealing said connection between said outlet and inlet openings against an outside of said ducts.  
     
     
       2. An occupant protecting device according to claim  1 , wherein said buckle and said tongue are coupled to each other, a gap for venting the gas to said outside of the ducts is defined between said outlet opening in said buckle-side duct and said inlet opening in said tongue-side duct. 
     
     
       3. An occupant protecting device according to claim  1 , further comprising small bores defined in the inlet opening in the tongue-side duct permitting passage of the gas and inhibiting passage of foreign matters. 
     
     
       4. An occupant protecting device comprising: 
       a buckle-side duct integral with a buckle supported on a seat; and  
       a tongue-side duct integral with a tongue supported on a belt, an inlet opening in said tongue-side duct being opposed to an outlet opening in said buckle-side duct upon coupling of said ducts,  
       said belt being expanded by a gas, generated by an inflater upon collision of a vehicle, supplied to said belt through said buckle-side duct and said tongue-side duct,  
       said belt, fitted over an outer periphery of said tongue-side duct, being tightened and fixed by a band, and a stopper provided on an end of said belt being brought into engagement with an edge of said band, said stopper preventing withdrawal of said belt from said tongue-side duct.  
     
     
       5. An occupant protecting device according to claim  4 , wherein said belt is in a double structure comprising an inner bag and an outer cover, and said stopper is a sewing portion for integrally sewing said bag and said cover to each other. 
     
     
       6. An occupant protecting device for a seat comprising: 
       a buckle supported on the seat and having a buckle-side duct with an outlet opening, said outlet opening being closed by a seal member having a lip portion at a peripheral edge thereof and a central breakable portion;  
       an expandable belt having a tongue, connectable to said buckle, and a tongue-side duct with an inlet opening, said inlet opening opposing said outlet opening when said tongue is coupled to said buckle; and  
       an inflater holding a pressurized gas to be supplied to said expandable belt through said buckle-side duct and said tongue-side duct,  
       wherein a connection is created between said outlet and inlet openings only when said central breakable portion of said seal member is broken and said lip portion of said seal member is moved towards said inlet opening by pressure from said gas when said gas is supplied from said inflater to said expandable belt, and said lip portion of the seal member provides a seal of said connection between said outlet and inlet openings against an outside of said ducts.  
     
     
       7. An occupant protecting device according to claim  6 , further comprising a gap, defined between said outlet opening and said inlet opening opposed each other when said tongue is coupled to said buckle, through which said gas is vented from said belt to said outside of the ducts after said inflater supplied said gas to said belt. 
     
     
       8. An occupant protecting device according to claim  6 , wherein said inlet opening in said tongue-side duct includes bores permitting passage of said gas and inhibiting passage of foreign matters. 
     
     
       9. An occupant protecting device according to claim  6 , wherein said belt is fitted over an outer periphery of said tongue-side duct and is fixed by a band, said belt further comprising a stopper abutting an edge of said band to prevent withdrawal of said belt from said tongue-side duct. 
     
     
       10. An occupant protecting device according to claim  6 , wherein said belt is fitted over an outer periphery of said tongue-side duct and is fixed by a band, said belt further comprising an inner expandable bag, an outer cover, and a sewing portion sewing said bag to said cover, said sewing portion abutting an edge of said band to prevent withdrawal of said belt from said tongue-side duct. 
     
     
       11. An occupant protecting device according to claim  1 , wherein said outlet opening is perpendicular to a length of said buckle-side duct, and said inlet opening is perpendicular to a length of said tongue-side duct. 
     
     
       12. An occupant protecting device according to claim  6 , wherein said outlet opening is perpendicular to a length of said buckle-side duct, and said inlet opening is perpendicular to a length of said tongue-side duct.